Lighting towns by electricity



(NoModeL) H. G. SPALDING.

Lighting Towns by Electricity- No. 235,914. Patented Dec. 28,1880.

N.FETERS, PHOTD-LI1HOGRAPHER. WASHINGTON. D C,

UNITED STATES ATENT FFICE.

HENRY C. SPALDING, OF BOSTON, MASSACHUSETTS.

LIGHTING TOWNS BY ELECTRICITY.

SPECIFICATION forming part of Letters Patent No. 235,914, dated December 28, 1880.

' Application filed November 10, 1880. (No model.)

To all whom it may concern:

Be it known that I, HENRS: O. SPALDING, of Boston, in the county of Suffolk and State of Massachusetts, have invented a certain new and useful Improvement in the Art of Lightin g Towns by Electricity, of which the following is a specification.

In another application for Letters Patent, now on file in the United States Patent Office, I have described an improvement in the art of lighting towns, which consists in the employment of groups or assemblages of electric lights, each group of a number of lights massed together, supported in an elevated position above the roofs of buildings, and the several groups arranged in such proximity to one another as to light the spaces intervening between them. In this system, which requires, in practice, the assembling in one group of quite a large number of lights, it is neither desirable nor feasible to put all the lights in one circuit, nor, on the other hand, is it practicable, in an economical point of view, to use an independent battery or machine for each individual light. It is therefore necessary to subdivide the group or assemblage of lights into lesser groups, each sub-group being in a circuit distinct from and independent of the others. Under this arrangement it becomes important to prevent the fluctuations of the light of any one sub-group from sensibly affecting the apparent amount of light derived from the entire or main group-or, in other words, to prevent fluctuations in the apparent amount of light derived from the whole assemblage of massed lights. his to this end that my present invention is directed; and it consists in subdividing each group or assemblage of massed lights into lesser groups, each sub-group being in an electric circuit separate and distinct from the others, and the lights composing each sub-group being so sethirty-two lights arranged in circle, and the arrangement contemplates the use of eight batteries or machines, one to each sub-group of four lights. In selecting the lights for each sub-group I take them from such points in the circle that they will be as far as possible removed from proximity to one another. For instance, as indicated in the diagram, the circuit controlled by batteryA contains the four lights 1 2 3 4; battery B, 5 6 7 8, and so on. Each light of each sub-group is thus separated from its nearest fellow by seven other lights of other sub-groups. It is manifest that under this arrangement fluctuations in the lights of any one sub-group would exercise no sensible influence upon the apparent amount of light derived from the whole assemblage, and that this amount, practically, would remain constant, notwithstanding occasional variations in the light of individual sub-groups.

For the purpose of illustration, I have put four lights in each circuit. It is apparent, however, that the number may vary. My experience, on the whole, is that it is not well to have less than four lights to one machine or battery, and, on the other hand, that it is not well to have less than four machines or batteries to one group or assemblage of massed lights; but I do not wish to be understood as restricting myself to these limits.

Having described my invention, what I claim, and desire to secure by Letters Patent,

The herein-described improvement on the system of lighting towns by groups or assemblages of electric lights massed together and supported in an elevated position, which consists in subdividing the group of lights into lesser groups, each sub-group being in an elec trical circuit distinct from and independent of the others, and the lights composing each subgroup being so selected as to be interspersed with and separated from one another by the lights of other sub-groups, substantially as hereinbefore set forth.

In testimony whereof I have hereunto set my hand this 9th day of November, 1880.

H. O. SPALDING. Witnesses:

E. A. DICK, N. 0. LANE. 

